Merge pull request #96 from HyperloopUPV-H8/backend/tcp-client-errors

[backend] TCP connections not reconnecting after link goes down

Author: jmaralo

backend/pkg/transport/network/tcp/client.go

@@ -53,6 +53,8 @@ type ClientConfig struct {
 	CurrentRetries int
 	// Backoff specifies the backoff algorithm for this client
 	Backoff backoffFunction
+	// AbortOnError specifies whether the client should abort on errors or keep trying to connect
+	AbortOnError bool
 }
 
 // NewClient inits a ClientConfig with good defaults and the provided information
@@ -66,8 +68,9 @@ func NewClient(local net.Addr) ClientConfig {
 
 		Context: context.TODO(),
 
-		MaxRetries: -1,
-		Backoff:    NewExponBackoff(defaultBackoffMin, defaultBackoffExp, defaultBackoffMax),
+		MaxRetries:   -1,
+		Backoff:      NewExponBackoff(defaultBackoffMin, defaultBackoffExp, defaultBackoffMax),
+		AbortOnError: false,
 	}
 }
 

backend/pkg/transport/transport.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"os"
 	"sync"
 	"time"
 
@@ -44,7 +45,8 @@ func (transport *Transport) HandleClient(config tcp.ClientConfig, target abstrac
 	for {
 		conn, err := config.Dial(network, remote)
 		if err != nil {
-			if !errors.Is(err, error(tcp.ErrTooManyRetries{})) {
+			if config.AbortOnError {
+				fmt.Fprintf(os.Stderr, "Error connecting to %s: %v\n", target, err)
 				return err
 			}
 
@@ -55,6 +57,14 @@ func (transport *Transport) HandleClient(config tcp.ClientConfig, target abstrac
 		if errors.Is(err, error(ErrTargetAlreadyConnected{})) {
 			return err
 		}
+		if err != nil {
+			if config.AbortOnError {
+				fmt.Fprintf(os.Stderr, "Error handling connection to %s: %v\n", target, err)
+				return err
+			}
+
+			continue
+		}
 
 		// Wait before trying to reconnect
 		config.CurrentRetries = 5
@@ -83,6 +93,12 @@ func (transport *Transport) handleTCPConn(target abstraction.TransportTarget, co
 		return err
 	}
 
+	if tcpConn, ok := conn.(*net.TCPConn); ok {
+		err := tcpConn.SetLinger(0)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error setting %s linger to zero: %v\n", target, err)
+		}
+	}
 	conn, errChan := tcp.WithErrChan(conn)
 	defer conn.Close()